Motor fuel



Patented Aug. 13, 1940 UNITED STATES PATENT OFFICE MOTOR ,FUEL

No Drawing. Application October 20, 1936, Serial No. 108,589

lCiaim.

The present invention relates to motor fuels. and relates moreparticularly to motor fuels comprising branched-chain oxygenated organiccompounds, and specifically aldehydes, esters and I ketones containingat least one branched-chain,

and/or hydrocarbon mixtures branched-chain aldehydes, esters or ketones.

A principal object of this invention is the improvement of theanti-detonation characteristics 19 of hydrocarbon motor fuels by theaddition thereto of one or more branched-chain aldehydes, esters orketones.

A further object of this invention is the improvement in the blendingvalue of hydrocarbon motor fuels with organo-metallic compounds such astetraethyl lead, by the addition to such fuels of one or morebranched-chain aldehydes, esters or ketones.

A further object of this invention is the im- I provement of thevolatility of hydrocarbon motor fuels by the addition thereto ofbranched-chain aldehydes, esters or ketones, and particularly suchcompounds having a boiling point below about 125 C.

I It has been known heretofore that volatile, straight-chain aldehydes,estersand ketones such as acetaldehyde, paraldehyde, acetone, methylethyl ketone, methyl acetate and ethyl butyrate are suitable for use inimproving the volatility 80 of hydrocarbon fuels such as gasoline, andsuch compounds have been employed particularly as constituents ofaviation motor fuels.

I have found that aldehydes, esters and ketones having one or morebranched-chains, are in II themselves, suitable for use as motor fuels,and are of particular utility as addition agents for improving theanti-detonation characteristics, volatility and blending qualities ofhydrocarbon motor fuels such as gasoline. The branchedchain aldehydes.esters and ketones which may be employed in accordance with my inventioncomprise essentially compounds having at least one primary, secondary ortertiary branchedchain aliphatic group and may be represented as by thefollowing formulae:

59 wherein either one or both R and R are branched-chain aliphaticradicals. If 'onlyone is branched, the other may be any other radicalsuch as aryl or straight-chain alkyl.

Branched-chain aldehydes, esters and ketones which may be employed asmotor fuels or as addicontainingtion agents for improving the qualitiesof hydrocavrnbon motor fuels, are exemplified by the follo ng:

Z-methyl pentanal-5,

CI-I3.CH(CH3) .CH2.CH2.CHO Z-methyl propanal, (CI-IahCILCHO 2-methylbutanal, CH3.CH2.CH(CH3).CHO

3-methylpentanal. CH:.CH2.CH(CH:)CH:CHO 2,2-dimethy1 propanal, (CH3)30.0110 2,2-dimethyl butanal, CHa.CH2.C(CH3)a.CHO 2,2,3-trimethylbutanal-i,

CH3.C(CH3) 2.CH(CH3) .CHO 2,2-dimethylbutyl-3 acetate,

- (CH3)2.C.C.(CH2) .O.CO.CH 1 2,4-dimethylpentyl-3 trimethylacetate,

[(CHa) z.CH]a.CH.O.CO.C(CHs) a Tertiary butyi acetate, CH3.CO;OC.(CH3)3Ethyl trimethylacetate, (CH3)3C.C0.0C2H5 Hexamethylacetone, (CI-Ia)aC.CO.C (CH3) 3 Mesityl oxide, CHJ.CO.CH=C(CH3)2 Isopropyl phenylketone, CsHs.CO.CI-I(CH3)2 The quantity of branched-chain aldehyde,ester or ketone required to effect the desired improvement in theanti-detonation characteristics of hydrocarbon motor fuels depends uponthe degree of improvement required, the source 40 or character of thehydrocarbon fuel to be improved, and the nature or structure of thecompound employed. In general. in a given motor fuel the anti-knock oroctane rating is proportional to (1) the quantity of the particularaldehyde, ester or ketone added and, (2) the original anti-knock oroctane rating of the fuel. The lower the original anti-knock rating ofthe fuel, the greater will be the relative increase for the addition ofa given quantity of the branchedchain compound. Furthermore, thequantity of aldehyde, ester or ketone required to effect the desiredimprovement in anti-knock rating is dependent, to a certain extent, uponthe structure of the compound. The more centralized" or 1 'My inventionmay be further illustrated by the following examples, wherein theanti-knock value s'or octane numbers tabulated were determined inaccbrdanoe with the A. S. T. M.-C. F. R. 'MethodDZlb'l-MT.

, Vol- I Voloctane Baseluel Anti-hum agent numperporbet a I cent centfonnsylvlfileltraight- 100 0 4i nguo 75 Isobutyraidehyde... 68 90Isopropyl formats. 10 48 75 d0 25 57 90 Secot tidllybutYlM- 10 49 a 90Tertiary butyl aoe- 10 48 tato. 76 o.- 25 69 ;75 Secondary any] 000- 25-oo Methylisobutylke- 1o 49 tone. 75 ..do 25 69 D0 Methyl isopropyl i048 7s Moihyltertiary buas so tylketone. 90 Mosityl oxide i0 51 compoundssuch as tetraethyl lead.

I have found that branched-chained adelhydes, esters'and ketones aredecidedly more effective as addition agents for improving the blendingqualities of motor fuels than is iso-octane which has been employedheretofore as an addition agent for aviation fuels. A branched-chainaldehyde such as isobutyraldehyde, when added to a hydrocarbon motorfuel permits the use of approximately 25% to less tetraethyl lead toproduce a blended fuel of a desired octane number,

.than does iso-octane in quantities corresponding to the quantities ofaldehyde used. Branchedchain aldehydes, esters and ketones other thanisobutyraldehyde behave similarly in improving both the blendingqualities and anti-knock rating of motor fuels.

While herein I have particularly described the use of branched-chainaldehydes, esters and ketones, per se, as motor fuels, and as additionagents for hydrocarbon motor fuels, I do not intend to limit myselfthereto but may employ such branched-chain compounds as addition agentsfor various types of motor fuels, including mixtures of petroleumhydrocarbons such as gasoline with alcohol or benzol; fuels produced bythe cracking and polymerization of hydrocarbon oils and gases; fuelsproduced by the decomposition and/or hydrogenation of carbonaceoussubstances; and fuels produced by the chemical polymerization ofunsaturated hydrocarbons. Furthermore, I may employ one or a mixture ofbranched-chain aldehydes. esters and ketones, and particularly thosehaving boiling points within the motor fuel boiling range or below about200 C., as fuels or as addition agents for motor fuels. Such oxygenatedorganic compounds contain at least one aldehyde, ester or ketone group,and at least one branched-chain aliphatic hydrocarbon group, all of saidcompounds being characterized by'the structure.

What I claim is: t

A fuel for internal combustion engines comprising a hydrocarbon mixtureof the motor fuel boiling range and a quantity of isobutyraldehydesufficient to substantially increase the anti-knock value thereof.

DAVID LIPKIN.

